Thanks for writing to us.
The muscle stiffness
in your back and the breathing problem may be related to a muscle spasm . A physical examination is necessary to find out the exact cause.
You need to consult an orthopedician for examination of swelling. The treatment usually involves rest with pain killers in combination with the muscle relaxants along with good physiotherapy
Meanwhile you can do a hot fomentation and apply a local analgesic
gel on the area to relieve the spasm.
Wishing you good health...
Dr Saurabh Gupta.